Abstract: Objective: To investigate the correlation between the cross-sectional area of erector spinae muscle and lung function in patients with non-small cell lung cancer(NSCLC). Methods: The clinical data of 92 patients with NSCLC were retrospectively analyzed.The pulmonary function measurement and chest CT examination in all patients were performed before surgery,and the pulmonary function indexes and related clinical information were collected.On the preoperative chest CT images of patients,the muscle outline of erector spinae muscle were identified and manually sketched,and the cross-sectional area of the erector spinae muscle were recorded. Results: There was no statistical significance in the lung function indexes among NSCLC patients with different lesion diameters(P>0.05).The cross-sectional area of erector spinae muscle in NSCLC patients was negatively correlated with the age(P<0.01),and positively correlated with the height and body mass(P<0.01).The cross-sectional area of erector spinae muscle was positively correlated with the forced expiratory volume in the first second,forced vital capacity,peak expiratory flow and expiratory flow rate at 75% of residual vital capacity(P<0.01),but there was not significant correlation between the expiratory flow rate at 50% of residual vital capacity and 25% of residual vital capacity(P>0.05). Conclusions: There is a correlation between the cross-sectional area of erector spinae muscle and lung function in NSCLC patients.